Pyrolysis
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Bioenergy > Technologies > Thermochemical technologies > Pyrolysis
Pyrolysis is a thermochemical conversion technology used to produce energy from biomass. It involves the heating of organic materials in the absence of reagents, especially oxygen, to achieve decomposition. When pyrolysis takes place in the presence of water, it is called hydrous pyrolysis.
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Types of Pyrolysis Technologies
Pyrolysis technologies can be categorized as being of two types:
- Fast Pyrolysis, and
- Slow Pyrolysis.
Fast Pyrolysis
Fast pyrolysis (Flash pyrolysis) takes place in less than two seconds with temperatures between 300 and 550 degrees Celsius. Char accumulates quickly in fast pyrolysis and must be removed frequently.
Fast Pyrolsis can be further categorized into the following:
- Ablative Fast Pyrolysis - pressure is applied to biomass to increase speed of decomposition through use of centrifugal or mechanical force. Larger particles of biomass can be used in this process.
- Cyclonic Fast Pyrolysis - also called vortex fast pyrolysis, separates the solids from the non-condensible gases and returns them to the mixer.
- Rotating Cone Fast Pyrolysis - uses a compact high intensity reactor in which biomass of ambient temperature is mixed with hot sand. Upon mixing with the hot sand, the biomass decomposes into 70% condensible gases with 15% non-condensible gases and 15% char.
Feedstocks for Fast Pyrolysis
- Any Organic Material
- Pretreatment: sorting
- Qualifications: none
Slow Pyrolysis
Feedstocks for Slow Pyrolysis
- Any Organic Material
- Pretreatment: sorting
- Qualifications: Waste must be pre-sorted and processed to <6 mm (1 to 2 mm. preferred) and <10% moisture content to assure high heat transfer rate.
Products
Products of pyrolysis include:
- Intermediate products
- Main Products (Final products)
- By-products
Advantages of Pyrolysis
- Generally a simple, low-cost technology capable of processing a wide variety of feedstocks producing gases, a bio-oil, bio-chemicals, and charcoal. A promising approach is the production of a bio-oil that can be used to power ethanol, biodiesel or other local industries facilities, and a charcoal. The charcoal is incorporated into the soil to promote its fertility and organic matter through synergistic processes between the soil, soil organisms, the roots fo the plants, water and the CO2 and nitrogen in the atmosphere.
Commercialization Status
- Pilot project- Cashton Greens Energy Park, Cashton WI. Demonstration Project- BEST Australia. Limited commercialization-Dynamotive, Canada.
Sustainability and Environmental Concerns
- By using waste streams and fully sustainable biomass, there are many environmental benefits including greenhouse gas stabilization.
Societal Impacts
- Properly structured, this technology provides waste collecting jobs for low-income people and opportunities for skilled technicians. This benefits communities through waste clean up (public health benefits), the use of local feedstocks and by providing decentralized power and fuels as well as charcoal to increase soil fertility and organic matter levels.
News
- Patent Pending: New Biofuel Developed at UGA, 21 May 2007 from Renewable Energy Access.com. Researchers at University of Georgia have developed an advanced form of pyrolysis that produces a bio-oil from wood chips or biomass pellets that can be used in conventional engines.
Note
This information was developed by the United States Environmental Protection Agency, Office of Research and Development, in cooperation with the Biomass Coordinating Council of the American Council on Renewable Energy (ACORE).
| Pyrolysis | edit | |
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Fast pyrolysis | Slow pyrolysis | ||
| Bioenergy conversion technologies | edit | |
| Technologies categorized by bioenergy processes: Biochemical: Aerobic, Anaerobic, Landfill gas collection (LFG), Biodiesel production, Ethanol production Technologies categorized by feedstock: Technologies by commercialization status: Analysis of technologies: Life-cycle analysis | ||
